Need help quickly (ASAP)

I know this may sound like I am going backwards, BUT there is a reason for it. I am in need of installing SQL 2000 for testting purposes in a testnet enviroment accessible by a production box.

Anyway, I have a win 2003 server currently installed with SQL 2005. I know that the two version can run side by side. And I have installed 2005 on a box running SQL2000.

Can I install SQL 2000 enterprise edition on a server that is currently running SQL 2005 without conflicting or corrupting the current instance.

Please any help ASAP would be highly appreciated. If not I need to come up with an alternative solution and that would mean building a new server from scratch and get into the testing enviroment by the end of day..